People are good at reacting to a common danger. Look at the Boxing Day Tsunami - people standing and watching the sea as they just didn't know what it was as they had never seen it before.

This month a 'hunger stone' appeared in the Danube, indicating the levels for pre-20th century famine.

And various other markers in many countries for 'the water reached this level', ironically, on the side of existing buildings.

Yet we build closer and closer to rivers because (flash) flood events happen rarely, and typically not in our lifetime.